Method for recovering ethyl pyrimidinol from pirimiphos-methyl synthesis wastewater
Ethylpyrimidine alcohol was recovered from methylpyrimidine phosphorus synthesis wastewater through a multi-step extraction and crystallization process, solving the problems of low efficiency and pollution in existing technologies. This method achieved high-purity and high-yield recovery of ethylpyrimidine alcohol, reducing production costs and improving resource utilization.
Patent Information
- Application Number
- CN202511766132.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-11-27
- Publication Date
- 2026-01-23
AI Technical Summary
Existing methods for recovering ethylpyrimidine alcohol from methylpyrimidine phosphorus synthesis wastewater are inefficient, have low product purity and yield, and cause environmental pollution. They also cannot be directly biochemically treated, increasing production costs.
A multi-step extraction method combining alkaline hydrolysis, decolorization, pH adjustment, and reflux crystallization was used to recover ethylpyrimidinol from methylpyrimidinium phosphate synthesis wastewater. The process included first extraction, alkaline hydrolysis, second extraction, decolorization, pH adjustment, reflux, and crystallization. Treatment with organic solvents and activated carbon improved product purity and yield.
The recovery of ethylpyrimidine alcohol with high purity (>99%) and high yield (>98.8%) has been achieved, reducing production costs and environmental pollution. The product can be directly used for the synthesis of methylpyrimidine phosphorus technical, thus improving resource utilization.
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Abstract
Description
TECHNICAL FIELD
[0001] The present application belongs to the field of organic chemical industry, and relates to a method for recovering ethyl pyrimidinol from methyl pyrimiphos synthesis wastewater. BACKGROUND
[0002] In methyl pyrimiphos synthesis wastewater, part of methyl pyrimiphos (formula I) is decomposed into 2-diethylamino-6-methyl-4-pyrimidinol, commonly known as ethyl pyrimidinol (formula II), which has low solubility in water. In alkaline conditions, the hydroxyl group on the pyrimidine ring of ethyl pyrimidinol is easy to form an alcoholate, mainly in the form of ions (such as formula III), while in acidic conditions, the diethylamino group on the ethyl pyrimidinol is easy to form a quaternary ammonium salt, as shown in formula IV. The wastewater containing ethyl pyrimidinol ions and ethyl pyrimidinol has strong biological toxicity and cannot be directly treated by biochemical treatment, causing environmental pollution. On the other hand, if ethyl pyrimidinol cannot be recovered from the wastewater of methyl pyrimiphos production, it is easy to cause waste of production resources and increase production cost.
[0003] .
[0004] In the prior art, solvent extraction method is often used to recover pyrimidinol from wastewater. However, when the known solvent extraction method is used to treat methyl pyrimiphos synthesis wastewater, the following defects still exist: 1. Low extraction efficiency. The main reason for low extraction efficiency is that the main existing form of ethyl pyrimidinol in wastewater is salt, the content of ethyl pyrimidinol is low, and the ethyl pyrimidinol salt cannot enter the organic phase. 2. The recovered product has high water content, many impurities, large viscosity, and a muddy state with a foul odor, and cannot be used for methyl pyrimiphos technical material synthesis, but can only be disposed of as hazardous waste or incinerated.
[0005] Therefore, it is of great significance to obtain a method for recovering ethyl pyrimidinol from methyl pyrimiphos synthesis wastewater, which has simple process, convenient operation, low recovery cost, mild reaction condition, high recovery efficiency, high purity of recovered product, and environmental friendliness, so as to solve the problem of methyl pyrimiphos synthesis wastewater pollution and realize the resource utilization of ethyl pyrimidinol. SUMMARY
[0006] The technical problem to be solved by the present application is to overcome the deficiencies and defects of the prior art, and to provide a method for recovering ethyl pyrimidinol from methyl pyrimiphos synthesis wastewater, which has simple process, convenient operation, low recovery cost, mild reaction condition, high recovery efficiency, high purity of recovered product, and environmental friendliness.
[0007] To solve the above technical problems, the present application adopts the following technical solutions.
[0008] A method for recovering ethyl pyrimidinol from methyl pyrimiphos synthesis wastewater, comprising the following steps: S1, adding organic solvent A to the methyl pyrimidophos synthesis wastewater to perform first extraction, obtaining organic phase A and aqueous phase A; S2, performing alkaline hydrolysis on the aqueous phase A obtained in step S1; S3, adding organic solvent B to the aqueous phase A after alkaline hydrolysis in step S2 to perform second extraction, obtaining organic phase B and aqueous phase B; S4, performing decolorization on the aqueous phase B obtained in step S3; S5, adjusting the pH value of the aqueous phase B after decolorization in step S4 to 6-7, collecting the precipitate to obtain ethyl pyrimidinol crude product; S6, adding solvent C to the ethyl pyrimidinol crude product obtained in step S5 to perform reflux, obtaining organic phase C and aqueous phase C; S7, performing cooling, crystallization, separation and drying on the organic phase C obtained in step S6 to obtain ethyl pyrimidinol.
[0009] The above method is further improved, in step S5, the pH value of the aqueous phase B after decolorization in step S4 is adjusted to 6.5-7 by using an acid; the precipitate is collected by using centrifugation and filtration.
[0010] The above method is further improved, in step S5, the acid is sulfuric acid or hydrochloric acid.
[0011] The above method is further improved, in step S6, the solvent C is methanol; the reflux is performed at a temperature of 60-100°C.
[0012] The above method is further improved, in step S7, the separation method includes centrifugal separation and filtration; the drying method includes ordinary drying and vacuum drying.
[0013] The above method is further improved, in step S1, the mass of the organic solvent A is 1%-4% of the methyl pyrimidophos synthesis wastewater; the organic solvent A is at least one of benzene, toluene, xylene and methyl isobutyl ketone.
[0014] The above method is further improved, in step S2, an alkali is added to the aqueous phase A obtained in step S1 to perform alkaline hydrolysis by adjusting the pH value of the aqueous phase A to 8-9; the alkali is at least one of sodium hydroxide and potassium hydroxide.
[0015] The above method is further improved, in step S3, the mass of the organic solvent B is 1%-4% of the methyl pyrimidophos synthesis wastewater; the organic solvent B is at least one of benzene, toluene, xylene and methyl isobutyl ketone.
[0016] The method is further improved, and in step S4, activated carbon is used to decolorize the aqueous phase B obtained in step S3; the mass of the activated carbon is 1‰-5‰ of the methrimbophos synthesis wastewater.
[0017] The method is further improved, and further comprises the following treatment: combining the organic phase A and the organic phase B for recovering the solvent.
[0018] In view of the difficulty in separating high-purity ethyl pyrimidinol from methrimbophos synthesis wastewater in the prior art, the application creatively provides a method for recovering ethyl pyrimidinol from methrimbophos synthesis wastewater, which sequentially performs first extraction, alkaline hydrolysis, second extraction, decolorization, pH value adjustment to 6-7, reflux, and temperature reduction crystallization on the methrimbophos synthesis wastewater, so as to effectively remove other organic matters in the wastewater, improve product quality, and obtain ethyl pyrimidinol with high purity and high yield, wherein the recovery rate of the ethyl pyrimidinol is greater than 99%, the purity is more than 99%, and the water content is very low; the obtained ethyl pyrimidinol can be directly used as a raw material to synthesize methrimbophos technical material, effectively improves the utilization rate of the ethyl pyrimidinol, reduces the consumption of the ethyl pyrimidinol, effectively solves the problem of odor in the original method for recovering the ethyl pyrimidinol, and significantly reduces the cost of three-waste treatment by outsourcing or incineration.
[0019] The method for recovering ethyl pyrimidinol from methrimbophos synthesis wastewater has the advantages of simple process, convenient operation, low recovery cost, mild reaction condition, high recovery efficiency, high purity of recovered product, environmental friendliness, and the like, not only solves the pollution problem of methrimbophos synthesis wastewater, but also realizes the resource utilization of the ethyl pyrimidinol, and shows very high environmental and economic benefits.
[0020] The reaction mechanism involved in the application is as follows: . BRIEF DESCRIPTION OF DRAWINGS
[0021] In order to make the purpose, technical scheme and advantages of the embodiments of the application clearer, the technical scheme in the embodiments of the application will be described clearly and completely below in combination with the drawings of the embodiments of the application.
[0022] Figure 1 The process flow diagram for recovering ethyl pyrimidinol from methrimbophos synthesis wastewater in the embodiment 1 of the application. DETAILED DESCRIPTION
[0023] The application will be described in further detail below in combination with the embodiments and drawings, but the embodiments of the application are not limited thereto. The reagents and instruments used in the following embodiments are commercially available.
[0024] Embodiment 1: A method for recovering ethyl pyrimidinol from methyl pyrimiphos synthesis wastewater, as shown in Figure 1 comprises the following steps: Step S1, first extraction: 4000g of methyl pyrimiphos synthesis wastewater is added to a 5L reaction bottle, 40g of toluene is added for normal temperature extraction, after thirty minutes, the upper organic phase and the lower aqueous phase are separated, and the organic phase is retained.
[0025] Step S2, alkaline hydrolysis of the aqueous phase: slowly add liquid alkali (sodium hydroxide) with a concentration of 50% to the aqueous phase until the pH stabilizes at 8-9, and stop adding liquid alkali.
[0026] Step S3, second extraction: 40g of toluene is added to the alkaline hydrolyzed aqueous phase reaction solution for extraction, and after stabilization, the organic phase and the organic phase after the first extraction are combined and solvent recovery is performed, and the aqueous phase is subjected to the next operation.
[0027] Step S4, add 20g of activated carbon to the aqueous phase for decolorization, and separate the activated carbon.
[0028] Step S5, adjust the acidity and alkalinity of the aqueous phase system, add 50% sulfuric acid to the aqueous phase to make the pH 7, at this time, a precipitate is produced in the aqueous phase, the precipitate is centrifuged and separated to obtain a crude ethyl pyrimidinol product.
[0029] In the present application, the pH value of the aqueous phase system is adjusted to 6-7 to ensure that it is changed to ethyl pyrimidinol. In addition, if in alkaline conditions, the salt will dissolve in water and will not precipitate.
[0030] Step S6, add 295g of methanol to the crude ethyl pyrimidinol, heat to 90℃, reflux, and after the ethyl pyrimidinol is completely dissolved, maintain for 20 minutes, and filter the salt in the system while it is hot after the temperature is complete.
[0031] Step S7, crystallize the organic phase in step S6 by slowly cooling, centrifuge at -5℃, dry, and obtain 27.5g of ethyl pyrimidinol with a content of 99.1% and a recovery rate of 99.6%, the obtained ethyl pyrimidinol is used for methyl pyrimiphos synthesis.
[0032] Example 2: A method for recovering ethyl pyrimidinol from methyl pyrimiphos synthesis wastewater, comprising the following steps: Step S1, first extraction: 4000g of methyl pyrimiphos synthesis wastewater is added to a 5L reaction bottle, 40g of toluene is added for normal temperature extraction, after thirty minutes, the upper organic phase and the lower aqueous phase are separated, and the organic phase is retained.
[0033] Step S2, alkaline hydrolysis of the aqueous phase: slowly add liquid alkali (sodium hydroxide) with a concentration of 50% to the aqueous phase until the pH stabilizes at 7 stop adding liquid alkali.
[0034] Step S3, second extraction: 80g of toluene is added to the alkaline hydrolyzed aqueous phase reaction solution for extraction, and after stabilization, the organic phase and the organic phase after the first extraction are combined and solvent recovery is performed, and the aqueous phase is subjected to the next step.
[0035] Step S4, 12g of activated carbon is added to the aqueous phase for decolorization, and the activated carbon is separated.
[0036] Step S5, the acid-base of the aqueous phase system is adjusted, 50% sulfuric acid is added to the aqueous phase to make the pH 7, at this time, a precipitate is produced in the aqueous phase, and the precipitate is separated by centrifugation to obtain the crude ethyl pyrimidinol.
[0037] Step S6, 295g of methanol is added to the crude ethyl pyrimidinol, heated to 90°C, and refluxed, and after the ethyl pyrimidinol is completely dissolved, the system is maintained for 20 minutes, and after the heat preservation is completed, the salt in the system is separated by hot filtration.
[0038] Step S7, the organic phase in step S6 is cooled and crystallized, centrifuged at -5°C, and dried to obtain ethyl pyrimidinol, the content of which is 99.3%, and the recovery rate is 99.2%, and the ethyl pyrimidinol is used for methyl pyrimiphos synthesis.
[0039] Example 3: A method for recovering ethyl pyrimidinol from methyl pyrimiphos synthesis wastewater, comprising the following steps: Step S1, first extraction: 4000g of methyl pyrimiphos synthesis wastewater is added to a 5L reaction bottle, 40g of methyl isobutyl ketone (MIBK) is added for normal temperature extraction, after thirty minutes, the upper organic phase and the lower aqueous phase are separated, and the organic phase is retained.
[0040] Step S2, alkaline hydrolysis of the aqueous phase: 50% liquid caustic is slowly added to the aqueous phase until the pH stabilizes at 7, and the addition of liquid caustic is stopped; Step S3, second extraction: 40g of toluene is added to the alkaline hydrolyzed aqueous phase reaction solution for extraction, and after stabilization, the organic phase and the organic phase after the first extraction are combined and solvent recovery is performed, and the aqueous phase is subjected to the next step.
[0041] Step S4, 20g of activated carbon is added to the aqueous phase for decolorization, and the activated carbon is separated.
[0042] Step S5, the acid-base of the aqueous phase system is adjusted, 50% sulfuric acid is added to the aqueous phase to make the pH 7, at this time, a precipitate is produced in the aqueous phase, and the precipitate is separated by centrifugation to obtain the crude ethyl pyrimidinol.
[0043] Step S6, 295g of methanol is added to the ethyl pyrimidinol crude product, heated to 90 DEG C, refluxed, and after the ethyl pyrimidinol is completely dissolved, maintained for 20 minutes, and after the temperature is maintained, the salt in the system is separated by hot filtration.
[0044] Step S7, the organic phase in step S6 is cooled and crystallized, centrifuged at -5 DEG C, dried, and ethyl pyrimidinol is obtained, and the content of ethyl pyrimidinol is 99.8%, the recovery rate is 99.0%, and the obtained ethyl pyrimidinol is used for methyl pyrimiphos synthesis.
[0045] In addition, the water content in the ethyl pyrimidinol products obtained by the embodiments 1-3 of the present application is 0.13wt%, 0.17wt%, and 0.11wt% respectively, which is much lower than that of the conventional solvent extraction method (10%).
[0046] The raw materials and equipment used in the present application are conventional raw materials and equipment in the art, unless otherwise specified; the methods used in the present application are conventional methods in the art, unless otherwise specified In summary, the method for recovering ethyl pyrimidinol from methyl pyrimiphos synthesis wastewater has the advantages of simple process, convenient operation, low recovery cost, mild reaction conditions, high recovery efficiency, high purity of recovered product, environmental friendliness, etc., wherein the content of ethyl pyrimidinol is greater than 99%, and the yield of pyrimidinol is greater than 98.8%, which not only solves the problem of wastewater pollution in methyl pyrimiphos synthesis, but also realizes the resource utilization of ethyl pyrimidinol, and shows very high environmental and economic benefits.
[0047] The above is only a preferred embodiment of the present application, and does not limit the present application in any form. Although the present application has been disclosed as above with a preferred embodiment, it is not intended to limit the present application. Any person skilled in the art can make many possible changes and modifications to the technical solutions disclosed above, or modify equivalent embodiments, without departing from the spirit and technical solutions of the present application. Therefore, any simple modification, equivalent replacement, equivalent change and modification made to the above embodiments according to the technical essence of the present application, all within the scope of the technical solutions of the present application, are still within the scope of protection of the present application.
Claims
1. A method for recovering ethylpyrimidinol from wastewater synthesized from milbemycin oxime, characterized by, The method comprises the following steps: S1, adding an organic solvent A to the methrimbophos synthesis wastewater to perform a first extraction, to obtain an organic phase A and an aqueous phase A; S2, performing alkaline hydrolysis on the aqueous phase A obtained in step S1; S3, adding an organic solvent B to the aqueous phase A after alkaline hydrolysis in step S2 to perform a second extraction, to obtain an organic phase B and an aqueous phase B; S4, performing decolorization on the aqueous phase B obtained in step S3; S5, adjusting the pH value of the aqueous phase B after decolorization in step S4 to 6-7, and collecting the precipitate to obtain a crude ethyl pyrimidinol; S6, adding a solvent C to the crude ethyl pyrimidinol obtained in step S5 to perform refluxing, to obtain an organic phase C and an aqueous phase C; S7, performing cooling, crystallization, separation and drying on the organic phase C obtained in step S6 to obtain ethyl pyrimidinol.
2. The method of claim 1, wherein, In step S5, the pH value of the aqueous phase B after decolorization in step S4 is adjusted to 6.5-7 by using an acid; and the precipitate is collected by using centrifugation and filtration.
3. The method of claim 2, wherein, In step S5, the acid is sulfuric acid or hydrochloric acid.
4. The method of claim 1, wherein, In step S6, the solvent C is methanol; and the refluxing is performed at a temperature of 60-100℃.
5. The method of claim 1, wherein, In step S7, the separation includes centrifugal separation and filtration; and the drying includes ordinary drying and vacuum drying.
6. The method according to any one of claims 1 to 5, characterized in that, In step S1, the mass of the organic solvent A is 1%-4% of the mass of the methrimbophos synthesis wastewater; and the organic solvent A is at least one of benzene, toluene, xylene and methyl isobutyl ketone.
7. The method according to any one of claims 1 to 5, characterized in that, In step S2, an alkali is added to the aqueous phase A obtained in step S1 to adjust the pH value of the aqueous phase A to 8-9 for alkaline hydrolysis; and the alkali is at least one of sodium hydroxide and potassium hydroxide.
8. The method according to any one of claims 1 to 5, characterized in that, In step S3, the mass of the organic solvent B is 1%-4% of the mass of the methrimbophos synthesis wastewater; and the organic solvent B is at least one of benzene, toluene, xylene and methyl isobutyl ketone.
9. The method according to any one of claims 1 to 5, characterized in that, In step S4, activated carbon is used to decolorize the aqueous phase B obtained in step S3; and the mass of the activated carbon is 1‰-5‰ of the mass of the methrimbophos synthesis wastewater.
10. The method according to any one of claims 1 to 5, characterized in that, The method further comprises the following treatment: combining the organic phase A and the organic phase B to recover the solvent.